The diversification of data link layer protocol is increasing with the development of space link in optical satellite network.Data encapsulation can realize the standardized data transmission.A key issue of using efficiency methods to encapsulate different types and different rates data in optical satellite network needs to be solved.A data encapsulation method of virtual channel and master channel joint optimization is proposed to solve the problem of different types and different rates data unification enc apsulation in optical satellite network.The methods of virtual channel encapsulation and master channel process ing are given,respectively. And their principles are analyzed.The virtual channel scheduling algorithm based on priority is proposed to optimize time conflict of frame scheduling in virtual channel,and to overcome th e shortcomings of low efficiency frame multiplexing in virtual processing.The service type of transmission frame is optimized to improve the frame transmission performance,and the influence of forward error correction co ding in master channel is analyzed by simulation.The results show that the frame transmission efficiency increases by 24.61% after using priority algorithm and the best coding scheme of master channel processing is th e concatena ted code of outer code for RS code and internal code for convolution code.